这是我在 OpenSSL 服务器模式下的程序,
SSL 和 BIO 变量的初始化部分:
map<int, SSL> m_SSLMap;
map<int, BIO> m_BioWriteMap;
map<int, BIO> m_BioReadMap;
int InitializeServerNegotiationMode(int iFd)
{
SSL *pServSslFd;
BIO *pWb, *pRb;
pServSslFd = SSL_new(m_pCtx);
assert(pServSslFd);
if ( SSL_version(pServSslFd) == DTLS1_VERSION)
{
pWb = BIO_new(BIO_s_mem());
pRb = BIO_new(BIO_s_mem());
assert(pWb);
assert(pRb);
SSL_set_bio(pServSslFd, pRb, pWb);
SSL_set_accept_state(pServSslFd);
}
m_SSLMap[iFd] = *pServSslFd;
m_BioReadMap[iFd] = *pRb;
m_BioWriteMap[iFd] = *pWb;
return INITIALIZATION_SUCCESS;
}
DTLS 数据到达服务器时的服务器模式协商操作:
int ServerModeDTLSNegotiation(int iChannel, const char *pBuff, const int iLen, int iFd)
{
SSL *pServSslFd;
BIO *pRbio;
BIO *pWbio;
pServSslFd = &m_SSLMap[iFd];
pRbio = &m_BioReadMap[iFd];
pWbio = &m_BioWriteMap[iFd];
char buff[4096];
memset(buff, 0, strlen(buff));
BIO_write(pRbio, pBuff, iLen);
if(!SSL_is_init_finished(pServSslFd))
{
int iRet = SSL_do_handshake(pServSslFd);
}
int iNewLen = BIO_read(pWbio, buff, 2048);
if(iNewLen>0)
{
char *pNewData = new char[iNewLen+1];
for(int i=0;i<iNewLen;i++)
pNewData[i] = buff[i];
m_pEventHandler->SendReply(iChannel, (unsigned char *)pNewData, iNewLen);
}
else
{
printf("[DTLS]:: HandShaking Response failed for this data,
return -1;
}
return NEGOTIATION_SUCCESS;
}
在这里,我附上了 Wireshark TCP-Dump 以便更好地监控该问题。
https://www.dropbox.com/s/quidcs6gilnvt2o/WebRTC%20DTLS%20Handshake%20Failure.pcapng?dl=0
现在,我对 SSL_CTX 变量的初始化充满信心。因为,有时握手会成功协商每个端口。但有时一两个端口的握手失败。我正在工作 5 天来解决 Google Chrome 的 WebRTC DTLS 服务器模式协商问题。但是我还没有找到这个问题的根本原因。